A very large family of flowering plants, Compositae (or Asteraceae),
comprising about 1,100 genera and more than 20,000 species, including the daisy, lettuce, and marigold. The composite plants are eudicots and are considered to be the most highly evolved plants. Their inflorescences are characterized by many small flowers arranged in a head that resembles a single flower and arises from an involucre of bracts. A head may consist of both ray flowers and disk flowers, as in the sunflower, of disk flowers only, as in the burdock, or of ray flowers only, as in the dandelion.